What should I do if my important medication is not available?

Good day,

Until now, I've been taking a medication called "atomoxetine" for my OCD and ADHD. The problem is that it's currently unavailable due to a shortage. The prescription for the medication was automatically renewed on my health insurance card.

Unfortunately, I now find myself in the dilemma that I no longer have a psychiatrist who could prescribe me a new medication. Although I've been looking for one and making appointments for some time, they won't be available until March of next year at the earliest.

I honestly don't know what to do, since I don't have anyone to talk to about it. I'm currently taking my Abitur, which is why I'm worried my grades will drop, especially since I'll be taking my exams next May.

I called the outpatient clinic in my area, as I had previously been treated there. They said they couldn't do anything either. Perhaps one could go to the emergency room of the psychiatric outpatient clinic and ask there. That seems very questionable to me, though.

Do you have any ideas? What do you think about the last option I wrote below?